The present invention relates to avionics systems for aircraft and more particularly to avionics systems for providing guidance to aircraft pilots when they encounter hazardous windshear conditions.
Wind conditions which are rapidly changing over time and/or short distances may cause serious aircraft safety problems. For example, suppose that an aircraft encounters a rapidly diminishing head wind on final approach to landing. As a result of the diminishing wind, the airspeed and lift of the aircraft may be greatly decreased. This can lead to an extremely dangerous situation with the aircraft rapidly losing maneuver capability.
Instrument systems presently exist for detecting windshear conditions. However, in the past, no effective avionics systems have been provided for guiding the pilot of an aircraft in recovering from hazardous windshear conditions. Further, only simple strategies were recommended for recovering from windshear conditions. Aircraft pilots were generally advised upon encountering windshear conditions to go advised upon encountering windshear conditions to go to full rated thrust and to fly the aircraft to its maximum angle of attack and thereby attempt to climb as quickly as possible. However, this solution ignores the problem that when the aircraft is at its maximum angle of attack, it will suffer from substantial drag and will have a reduced stall margin. If the windshear becomes more severe, the pilot may find the aircraft suddenly beyond the point of its safe maximum angle of attack. The performance of the aircraft may thereupon be seriously decreased and the pilot may find himself in a dangerous situation. Consequently, a need exists for an improved strategy for dealing with windshear conditions and a system for providing guidance commands to the pilot for directing the aircraft in recovering from a windshear situation.
It is an object of the present invention to provide an avionics system which embodies an improved strategy for recovering from hazardous windshear conditions affecting an aircraft in flight.
It is a further object of the present invention to provide an avionics system which provides guidance to an aircraft pilot which will allow the pilot to recover from windshear conditions in a safe and effective manner in accordance with the severity of the flight situation of the aircraft.
It is another object of the present invention to provide an avionics system which takes account of several factors affecting the performance of the aircraft in providing an intelligent strategy for recovering the aircraft from a windshear situation.
It is a further object of the present invention to provide an avionics system which supplies guidance directives to an aircraft pilot which are consistent with normal flying techniques and may be easily followed by the pilot in manuevering the aircraft.